Normal thermal stopping device with non-critical vane spacing
First Claim
1. A normal terminal stopping device, comprising:
- an elevator hoistway terminal zone position checkpoint detection means utilizing a binary coding method for providing a binary coded output signal indicative of unique position checkpoints in an elevator hoistway terminal zone;
decision means, responsive to said binary coded output signal, for learning and retrieving a velocity reference signal corresponding to a position checkpoint associated with said binary coded signal and for comparing said velocity reference signal to a velocity command signal indicative of an actual velocity of the elevator car in said elevator hoistway for causing the elevator car to travel with a velocity corresponding to the velocity reference signal in the presence of said velocity command signal being greater than said velocity reference signal when traveling toward a terminal landing.
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Abstract
A normal terminal stopping device (NTSD) using terminal zone position checkpoint detection with a binary coding method to identify a checkpoint within a terminal zone, and a digital shaft encoder mounted on the shaft of the hoist motor to determine a car position relative to a target stopping point. A microprocessor-based controller is used to compare a velocity command signal to a velocity limit reference. If the velocity command exceeds the velocity limit, the NTSD functions will take over to cause the elevator car to decelerate at the NTSD rate. In particular, the velocity limit reference is computed according to lead compensation and curve shaping techniques to attain better drive tracking characteristics of the motion controller. Binary coded checkpoints are used to eliminate error introduced in a car position derived from a motor shaft digital encoder. The normal terminal stopping device and method according to the present invention is less sensitive to the vane spacing as compared to the conventional NTSD designs.
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Citations
14 Claims
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1. A normal terminal stopping device, comprising:
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an elevator hoistway terminal zone position checkpoint detection means utilizing a binary coding method for providing a binary coded output signal indicative of unique position checkpoints in an elevator hoistway terminal zone; decision means, responsive to said binary coded output signal, for learning and retrieving a velocity reference signal corresponding to a position checkpoint associated with said binary coded signal and for comparing said velocity reference signal to a velocity command signal indicative of an actual velocity of the elevator car in said elevator hoistway for causing the elevator car to travel with a velocity corresponding to the velocity reference signal in the presence of said velocity command signal being greater than said velocity reference signal when traveling toward a terminal landing. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of providing safety regarding the stopping of an elevator car in an elevator hoistway terminal zone comprising the steps of:
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receiving a binary coded sensed output signal having a magnitude indicative of one of a plurality of position checkpoints in the hoistway terminal zone; retrieving, in response to said binary coded sensed output signal, a velocity reference signal associated with said one checkpoint; retrieving the car velocity command signal having a magnitude indicative of an actual velocity of the elevator car moving in the hoistway terminal zone; and comparing said car velocity command signal to said velocity reference signal for causing the elevator car to travel with a velocity corresponding to said velocity reference signal in the presence of said velocity command signal being greater than said velocity reference signal. - View Dependent Claims (14)
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Specification